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Potamogeton The main task is to clarify geographical and ecological patterns, relations with close species of these forms in the area. P. x nitens P. x sparganiifolius Hybrids are very characteristic for the genus. They occurs frequently and may be abundant in habitats, especially in rivers. P. distinctus P. fryeri Species from P. nodosus group with the main range in tropical area. Isolated localities far to the north. P. richardsonii P. strictifolius North American species close to P. perfoliatus and P. rutilus respectively. P. richardsonii differs by fimbriate stipules, P. strictifolius by larger number of leaf veins.

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Batrachium The main task is to clarify taxonomical status, relations with close species of these forms. European complex of river forms B. pseudofluitans Originated from hybridization of different species. River forms from Kamchatka and other places known as B. ashibetsuense and B. yezoense These forms are similar to European B. pseudofluitans. B. mongolicum B. aquatile B. floribundum B. dichotomum These heterophilous species are very close one each other. Their relations are still unclear.

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Сlose to U. intermedia, impossible to de- terminate without flowers or microscopy. Urticularia stygia Сlose to U. intermedia, impossible to de- terminate without flowers or microscopy. Myriophyllum sibiricum No M. spicatum in the area. This terrestrial form looks like endemic M. ussuriensis. Myriophyllum verticillatum This terrestrial form looks like endemic M. ussuriensis. Callitriche subanceps Doubtful species close to C. palustris. Other genera

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CONCLUSION 1. Composition of aquatic macrophytes in the northern Russian Far East will be changed based on extensive field researches and study of herbarium collections. 2. Number of species will be preliminary the same because of including of new taxa and excluding critical and misidentified forms. 3. Diversity of cryptogamic macrophytes should be much larger than known to date. 4. Extensive field investigations, critical study of the most genera of aquatic macrophytes in the area are required for understanding their diversity, geographical and ecological patterns, biology in extreme climate conditions of the northern Russian Far East.

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The research are supported by Russian Foundation for Basic Research (projects №№ , THANKS for attention ***